I. Field of the Invention
This invention relates generally to pacing defibrillation and hybrid lead wires that are connectable to an implantable cardiac rhythm management device, and more particularly relates to a lead design that electrically and mechanically couples two leads to a single port in a header assembly of the implantable device. The lead may be unipolar, bipolar or multipolar and includes an adapting member formed within the lead body, wherein a port is formed in the adapting member suitable for receiving a terminal end of an additional lead. The lead of the present invention is adaptable as a pacing, defibrillation, or hybrid pacing/defibrillation lead.
II. Discussion of the Related Art
A cardiac rhythm management device capable of pacing or defibrillating a patient""s heart typically includes a pulse generator having an electronic circuit and power supply contained to within a metal casing, commonly referred to as xe2x80x9cthe canxe2x80x9d. A lead, capable of transmitting a therapeutic electrical signal generated by the pulse generator to the heart, is electrically coupled to the electronic circuit of the pulse generator. A xe2x80x9cheaderxe2x80x9d having a receptacle or port is commonly provided in order to xe2x80x9cplugxe2x80x9d the lead into the rhythm management device and electrically couple the lead to the electronic circuit contained within the can. Over the years, the receptacles located in the header of the implantable cardiac rhythm management device and the terminal connector end of a corresponding lead have been standardized by the International Standards Organization (ISO). In the standard connector and receptacle arrangement, a port corresponding to each lead terminal connector end is formed in the header portion of the rhythm management device. When two or more leads are required, a separate receptacle is formed in the header for each corresponding lead""s terminal connector end.
During the administration of certain pacing or defibrillation therapy it may be desirable to administer the same pacing therapy to two or more separate leads. For example, it may be desirable to transmit the same pacing signal through a left and right ventricular lead. In order to electrically couple the leads to a single receptacle of the cardiac rhythm management device, it is current practice to interconnect the right and left ventricular leads with a separate adapter and sleeve. The terminal connector ends of each lead plug into corresponding ports formed in the adapter. The adapter then plugs into a corresponding receptacle of the cardiac rhythm management device. Utilizing an adapter and sleeve to interconnect two or more leads increases the required number of sealing connections and overall size of the implanted device.
Fain et al. in U.S. Pat. No. 6,679,026 (the ""026 device) describes a header adapter that provides at least one port in the header adapter that is sized differently than any of the header lead connector ports. The header adapter of the ""026 device, in essence, is an in-line coupling to accommodate various sized lead terminal connector ends. The header adapter of the ""026 device does not reduce the number of required header ports and further increases the number of required sealing connections. Hence, there is a need for an adapting member that interconnects two leads without increasing the required number of header ports or sealing connections. The present invention addresses these and other needs.
The purpose of the present invention is to provide an adapting member integrated into a main lead body, such that two leads may be electrically coupled together, thereby reducing the number of ports required in a corresponding header assembly of an implantable device. A terminal connector end of a unipolar lead may be coupled to the adapting member, such that a conducting wire of the unipolar lead is electrically coupled to a predetermined conducting wire of the main lead. The lead of the present invention includes an electrically insulating main body portion, at least one terminal connector, at least one electrode, at least one conductor, and the adapting member. The insulating main body, terminal connector, electrodes, and conductors may all be of a suitable construction known to those skilled in the art.
The lead of the present invention has a proximal and distal end, wherein terminal connectors are attached to the proximal end of the main body. The terminal connectors are adapted for coupling the terminal end of the lead to an implantable medical device. The lead may include one or more conductors for unipolar or bi-polar pacing and accordingly may include one or more terminal connectors electrically coupled to the proximal end of the conductors. The electrodes are embodied within a distal end portion of the main body portion and electrically connected to a distal end of each corresponding conductor.
The adapting member extends from the lead and may be formed as part of the electrically non-conducting main body portion of the lead. The adapting member includes a main housing having a port formed therein. The port has a terminal block engaged within the port and is adaptable for receiving and securing a terminal connector of the second lead thereto. A jumper wire is embedded within the adapting member and interconnects the terminal block contained within the port to a preselected one of the conductors insulated by the main body of the lead. When the terminal connector of the second lead is coupled to the terminal block, the preselected conductor of the main lead and the conductor of the second lead are electrically coupled in parallel. The jumper wire may include an outer electrically insulating layer, thereby further insulating the inner conductive wire.
The adapting member may extend from the lead adjacent the proximal end of the main body, such that the adapting member engages the header assembly of the implantable medical device when the lead is plugged into the header. When the adapting member engages the header assembly, the housing of the adapting member may have an aperture extending therethrough such that the aperture aligns with another header port of the implantable medical device. Alternatively, this aperture may be utilized to engage suturing material therethrough to thereby secure the adapting member to a desired location in the patient. Further, the adapting member may be contoured congruent with the shape of the header to form an overall continuous member of the implantable medical device.
It is accordingly a principal object of the present invention to provide an adapting member integrated into a lead body, wherein two electrically interconnected leads may be coupled to a single port of a lead header assembly of an implantable device.
Another object of the present invention is to provide an adapting member integrated into a lead body capable of electrically coupling bi-polar and unipolar leads to a header assembly of an implantable device.
Yet another object of the present invention is to provide a lead that reduces the required overall size of the header assembly of the implantable medical device.
Still another object of the present invention is to provide an adapting member integrated into a lead body capable of coupling two leads to a single port of a header and providing a passage for a third lead terminal connector to pass through the adapting member and engage another port of the header assembly.
These and other objects as well as these and other features and advantages of the present invention will become readily apparent to those skilled in the art from a review of the following detailed description of the preferred embodiment especially when considered in conjunction with the accompanying drawings in which like numerals in the several views refer to corresponding parts.